Why keep pressure to "lowest possible" found in sl

[Steve_in_Md]

This is a great board. I just joined and got several helpful and friendly response. Thanks
I am perplexed about the pressure settings. After my sleep study, the technician said that the pressure she determined was "5cm and she tried to get it down to 4cm, but 5cm was necessary."
Then when I got an autotitrating unit, it determined that 90% of the time the pressure needed was below 9cm and that I had 8 apnea episodes each hour.
It seems to me that if the technician determines the "lowest possible" pressure during the sleep study, that there might be times that the pressure needs to be higher - for allergies, deep sleep or whatever.
So, it seems to me that my pressure should be 10cm or so to reduce the number of episodes per hour.
Also, a question on the titrating mode - when on this mode does it go way down from time to time during the night and cause episodes? So that it is better to have a steady cpap pressure set rather than to use the auto mode all of the time. Thanks for your help.

[Slinky]

Welcome to the forum. You've come to the right place to get some answers to your questions.

I'm still relatively new at this CPAPping bit myself, almost a year since I started CPAP - but - my understanding is that during a titration study the intent is to titrate to the highest pressure that stops or prevents most apneas w/o causing central apneas. Perhaps what your sleep tech meant was she was trying to determine the lowest pressure that still prevented apneas and 4 cms of pressure just was too low.

Some people w/apnea do better on CPAP when they have some exhalation pressure relief from the inhalation pressure needed to prevent or stop apneas. So maybe she was trying to determine how much expiration pressure relief you might need.

It depends on the individual patient whether they will do better w/a pressure range or with a set pressure. Many w/autoPAPs use them most of the time as straight CPAP and only use them in auto mode on occasion. Others seem to do better leaving their autos in auto mode w/a set pressure range.

There will be others, more experienced, who can better answer your questions respond shortly, I'm sure.

[Snoredog]

Sounds like an inexperienced tech to me. Most labs start you off at 5 cm because even they know you would have a hard time breathing normally at 4 cm.

Forget what the lab said, put your Minimum to 6 or 7 and the Max above your last 90% found pressure. If AHI remains higher than you like start bumping up the Minimum until it drops to acceptable levels.

The only reason you would want the Minimum down lower is to improve tolerance with the machine such as with insomnia or aerophagia.

Many masks require 6 to 6.5 cm pressure just to flush out exhaled CO2, get it lower than that and you may just be rebreathing your own CO2 most of the night, that will leave you a nice migraine in the morning.

[msheda]

might try to keep it low for aerophagia.

my AHI is down, but my FI is way up!

[Wulfman...]

This is a great board. I just joined and got several helpful and friendly response. Thanks
I am perplexed about the pressure settings. After my sleep study, the technician said that the pressure she determined was "5cm and she tried to get it down to 4cm, but 5cm was necessary."
Then when I got an autotitrating unit, it determined that 90% of the time the pressure needed was below 9cm and that I had 8 apnea episodes each hour.
It seems to me that if the technician determines the "lowest possible" pressure during the sleep study, that there might be times that the pressure needs to be higher - for allergies, deep sleep or whatever.
So, it seems to me that my pressure should be 10cm or so to reduce the number of episodes per hour.
Also, a question on the titrating mode - when on this mode does it go way down from time to time during the night and cause episodes? So that it is better to have a steady cpap pressure set rather than to use the auto mode all of the time. Thanks for your help.

Yes. At some point, the pressure will drop back down to a lower (or lowest) level and allow some events to occur before the increasing pressure can stop or prevent them.

Changing pressures CAN be sleep-disturbing/disrupting for some people.

In the majority of cases, it IS better to use a single pressure.

If used in Auto mode, a narrower range of pressure is better than wide open and the bottom pressure needs to be positioned where it will prevent the majority of events before they occur.

There is no "one answer fits all" for this therapy, but if a person has a multi-mode machine and the software to monitor their therapy, the patient/user CAN optimize their therapy for best results.

And......"best results" and "compliance" SHOULD be what the medical community would want.......not just your money.

Den

[RosemaryB]

My lab tech had no credentials, though she was trying to get them and had failed the test for credentialling and only had one more try. She was very sure of herself, however. In her sureness she had a lot of things wrong, like mouth breathing wasn't a problem. She also told me that the mask I wore during the sleep study was the one I HAD to choose for treatment. This lab does not sell equipment. I debated her on these points, but she was VERY SURE of her information.

Another thing was that she announced to me, BEFORE I'd even put the mask on that she thought I would need only a pressure of 4 or at most 5. I have moderate sleep apnea. She titrated me starting at 4, moving soone to 5 and left me there all night. However, at home, with my data capable machine, I discovered that I still had an AHI of 7.0-8.0 with this pressure. Not to mention the difficulty breathing.

I changed my own pressure gradually, using an auto and found that a pressure of 8.5 or 9 seems about right. With that pressure I feel great and also have an AHI of 1.0 or less.

I told my doctor about this and suggested he not recommend this lab to anyone else. I shudder to think of the damage a person like this does to people who don't have access to this board. Perhaps I should picket the lab with a sign that says "Don't trust their information, log on to SLEEPTALK.COM for accurate information."

People like this are responsible for the 50% noncompliance rate we see for those who get cpap. End of rant.

[Wulfman...]

Rosemary,

Don't know if you meant the website you mentioned......I did a search on it and it seems to be a site for children. If you didn't mean that one, you could edit your post to say "CPAPTALK.COM".

Den